Pump for oil burners



March 10, 1931. F, FlscHER ET AL I 1,796,195

PUMP FOR OIL BURNERS Filed March 21. 1927 2 Sheets-Sheet l I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I INVENTOR March 10, 1931. F, FlSCHER 'E1' AL 1,796,195

` PUMP FOR OIL BURNERS Filed March 21, 1927 2 Sheets-Sheet 2 INVENTOR Patented Mar. 10.1931

' UNITED STATES PATENT OFFICE FRANK FISCHER, OF LABCHMONT, AND GUDMUND SIVERTSEN, OF BROOKLYN NEW YORK, ASSIGNORS T GRANT OIL BURNER CORPORATION OF DELAWABE, OF NEW YORK, n. Y.

PUMP Fon oIL BUBNER Application filed March 21, 1927. Serial No. 177,070.

- the more minute adjustments to the particular furnace involved.

Another object is to avoid small restricted passages likely to clog.

Another object is to cheapen the construction of the several pumps by combining them into a speciallv designed unit.

Another object is to facilitate accuracy of construction.

rl`hese and other objects are attained by the combination of parts illustrated in the accompanving drawings in which- Fig. 1 is a longitudinal Vertical section of our pumping unit, showing the motor direct-connected through a flexible coupling.

Fig. 2 is a transverse section taken on line AA of Fig. 1, showing the supply-pump gears. i

Fig. 3 is a transverse section taken on line BB of Fig. 1, showing the air-pump.

Referring` now to the drawings in detail: 1 is the out-board end-section of the pump casing. containing the oil-strainer 2 which is open at the lower end and carried by the plug 3. as indicated. For convenience, the alternate Sections of the pump casing Will be referred to as disc-Sections and houslng-secticns, the housing-sections surroundlng the faces of the gears and the disc-Sections enclosing the sides thereof.

4 is a pipe nipple connecting With the strainer cavity at its upper end, and With the forms a reservoir or sum 7 for catching any surplus oil which is not ed to the burner.

8 is a hole through which oil passes front the strainer to the inlet of the supply-pump composed of gears 9 and 10 in housing-section 11.

Disc-section 12 contains drilled passagel.r

for conveying the discharged oil froimthe v supply-pump gears 9 and 10 to the elbow .14.

15 is an adjustable needle which forms a needle-valve 16 with the discharge-end of elbow 14. Valve 16 nray throttle but cannot entirelv close, the passage of oil upward into sump 7.

17 is a drilled hole forming a branch passage from discharge passage 13 to the lower side of another needle-valve 18 carried in disc-section 12.

19 represents a drilled hole or passage for conveying the discharge from needle-valve 18 into the corresponding hole 20 formed in 'housing-section 21.

Housing-section 21 forms the casing of the air-pump (or air and oil mixing-pump), which pump has a pair of two-teeth gears or impellers 22 and 23, of the Root blower type.

In the lower central part of section 21 is formed the outer wall of an annular charnber 24 connecting With hole 20. The inner Wall is formed by nipple 26.

Passing through the center of annular chamber 24 is air intake passage 25 formed in nipple 26, connecting With the upper interior of sump 7. Sump 7 receives its air supply through suction ports 27.

Disc-section 28 contains discharge passage 29 and discharge nipple 30 for conveying surplus oil from the sump 7 back to the storage reservoir. The storage reservoir and connecting pipe are not shown, but willl be understood to connect With the lower end of nipple l30.

31 is another nut similar to 5 for holding the combination pump housing fast to the base 6.

Housing-section 32 contains return-pump gears 33 and 34 for pumping oil from sump 7 to the storage reservoir. Gear 34 is not shown in the drawing, but is located on shaft 40 and bears the same relation to gear 33 as gear 10 does to gear 9 in Fig. 2.

35 is the drive-end disc-section, having formed therein the return-pump suction passage 36,7connectingl With suction nipple 37 which extends to 'within a short distance of the bottem'of sump'7.

Disc-section 35 also contains oil drain-pasi sage.38 for conveying any oil leaking along the drive shaft 39, back-'to sump 7.-

.All of the -above gears and impellers arel 'in a Chamber '42 Where shaft 39 extends to sumap throughV disc-sectiony35. This collar 41 is designed to throw any oil leaking outward alo the shaft 39,'into chamber 42, from whic it' is drawn through-'drain passage 38 held together by tie bolts 45.

Motor 46 is mounted on base 6 and, directlyconnected through flexible coupling 47 to drive-shaft 39. i f' Obviously, a'rasing built asabove, with alternate dlsc and housing-sections, presents a number .of advantages. ,The housing-sections can be bored straight through and the exact width obtained by grinding the'parallel sides to the proper'thickness to fit the ends of the gears snugly. In'this way, the minimum running clearances for the gears, so essential for high efliciency in this type of pump, are readily obtained. This construction is both economical and precise, and insures leak-proof joints between the Sections of the casing. The strainer, as assembled in the first disc.- section, is readily removed for cleaning or replacement. v i

The .operation of our pump is as follows .v Oil is entrained' from the reservoir (not shown) through' nipple 4, strainer 2 and suction passage 8 into housing section 1.1, by-

means of supply-pump gears 9 and 10; and is discharged through passages 13 and 17 and. holes 19 and 20 to the mixing-pump and the 'surplus oil 'through elbow 14 and needlevalve 16,7into sump 7. w

Needle valve '16, being partly closed, imposes a back pressure on the `oii in passage 13, thereby forcing the portion of ,oil to be burned through passage`17, needle-valve 18,

passages 19 'and 20, to annular chamb'er 24.

' The amount of oil reaching Chamber 24 is obup by the. incoming' air and Vdischarged through pipe 43 and nozzle 44 into the furnace.

The surplus oil discharged through needlevalve 16 into sump 7, is entrained through suction nipple 37 and passages 36 by gears 33 and 34 of the 'return-pump; and is discharged through passage 29 and discharge nipple 30 back to w the storage reservoir. This completes the cycle of oil and air through :the

'Without needle valve 16, it is obvious that the maximum amount of oil which could be delivered through passage 17 to the nozzle 44 (with needle-valve 18 wide open) would depend upon the back-pressure produced by the friction of the oil passing through elbow 14 into sump 7; and in order to increase the flow to the nozzle 44 it is necessary to'increase the friction. This can readily be done in the construction shown by screwing down on needle 15, which is so contrived that it may throttle the oil but may Iiot completely close needle-valve 16. w

Needle-valve 16 is thus used merely to ad'apt the pump to large or small furnaces; while needle-valve 18 1s employed to make the more minute adjustments of the pump to the particular' furnace in which it is installed.

In ractice, needle-valve 16 is closed only enoug to by-pass the maximum amount of oil required for a given furnace, when needle-valve 18 is wide open. Then this maximum flow is reduced to normal requirements by a artial closing of needle-valve 18` It 1s apparent thatby means of these two valves, a minute adjustment of the oil delivered to .the nozzle may be made, without throttlin either valve to a small size orifice; and pro ability of stoppage is thereby avoided.

Having thus fully described our invention, Whatwe claim is new, and desire to secure by Letters Patent, is as follows:--

1. In a pumping unit for oil burners, a sump, a pair ,of parallel shafts, a sectional casing consisting of alternately disposed housing-sections and disc-Sections, the housing Sections being open on both sides and the disc-Sections abutting and 'closing the sides of the housing-sections, a pair of oil supplypump gears, a pair of air-pump impellers, and a pair of oil return-pump gears mounted on the shafts in the housing-sections, one of the disc-Sections having formed therein a discharge passage for conveying oil from the supply-pump gears to the impellers and a bypass from the discharge-passage to the sump, and a conduit for conveying surplus oil from the sump to the return-pump.

2. .In a pumping unit for burners, a sump, a sectional casing consistin g of alternately disposed housing-sections and disc-Sections, the housing-sections being open on both sides and the disc-Sections abutting and closing the sides of the housing Sections, a pair of fuel supply-pump gears, a pair of air-pump impellers, and a pair of fuel return-pump gears ,in the housing Sections, a conduit for conveying surplus fuel from the sump to the return-pump gears, one of the disc-Sections having formed therein a discharge-passage for conveying` fuel from the supply-pump gears to the impellers and a by-pass from the discharge-passage to the sump, and throttling means at the discharge-end of the by-pass for creating a back pressure of fuel toward the impellers.

3. In a pumping unit for oil burners, a sump, a sectional casing consisting of alternatelyv disposed housing-sections and disc- Sections, the housing-sections being open' on both sides and the disc-Sections abutting and closing the sides of the housing-sections, 'a pair of oil supply-pump gears, a pair. of airpump impellers, and a pair of oil returnpump gears in the housing Sections, a conduit for conveying surplus oil from the sump to the return-pump gears, one .of the disc-sections having formed therein a dischargepassage for conveying oil from the supplypump ears to the impellers and a by-pass from t e discharge-passage to the sump, a control-valve in the discharge passage to control the amount of oil admitted to the impellers, and a 'throttle-valve at the dischargc end of the by-pass to control the back pressure of oil a ainst the control-valve.

4. n a pumping unit for burners, asump having an air inlet opening formed therein, a casing, the casing having formed therein a casing, the casing having formed therein an air-pump compartment and a fuel supplypump compartment and a fuel return-pump compartment With individual inlet and outlet passages for each compartment and a bypass connecting the outlet of the supplypump compartment to the inlet of the airpump compartment, restricting means in the outlet from the supply-pump compartment, a conduit connecting the sump With the outlet of the supply-pump compartment, another conduit connecting the sump with the inlet to the air-pump, and a third conduit connecting the sump with the return-pump compartment so as to form acontrolled passage for liquid-fuel from the supply-pump compartment to the air-pump compartment and another passage for surplus fuel from the supply-pump compartment to the returnpump compartment.

5. VIn, a pumping apparatus for oil burners, a source o oil supply, a surplus-oil sump having an air inlet opening formed therein, an air and oil mixing-pump mounted above the sump, a conduit connecting the mixing-pump With the sump so as to convey air from the sump to the mixing-pump .when the pump is running and to convey oil drainage from the miXing-pump to the sump when the pump stops running, and oil return-pump forconveying the surplus oil from the sump to the source of supply, an oil supply-pump having an linlet communicating with the sourceA of supply, and a branched conduit connecting the discharge of the supply-pump with both. the mixing-pump and the sump, the said branched conduit being so disposed as to convey an adequate supply of oil to the mixingpump and any surplus oil to thesump.

6. In a pumping apparatus for oil burners, a source of oil supply, a surplus-oil sump, a positive displacement air and oil-mixingpump mounted above the sump, said mixing pump having an air inlet opening formed therein, a conduit connecting the mixingpump With the sump so as to convey oil drainage from the mixing-pump to the sump When the pump stops running, an oil return-pump for conveying surplus oil from the sump to the source of supply, an oil supply-pump having an inlet communicating With the source of supply, a three branched conduit for conveying oil from the supply-pump jointly to the mixing-pump and to the sump, and restrictive means in the conduit branch leading to the sump for increasing the flow of oil through the other conduit branch to the mixing-pump, and anotherI dischar e conduit for conveying air and oil mixtur'e ing-pump to the burner.

7. In a pumping apparatus for oil burners, a source of oil supply, a surplus-oil sump, a positive displacement air and oil mixingpump mounted above the sump, said mixingpump having an air inlet opening formed therein, a conduit connecting the mixingpump With the sump so as to convey oil drainage from the miXing-pump to the sump when the pump stops running, an oil return-pump for conveying surplus oil from the sump to the source of supply, an oil supply-pump having an inlet communicating with the source of om the mixsnpply, a two branched discharge conduit for conveying oil from the supply-pump jointly to the mixing-pump and to the sump, and throttling means in both branches of the discharge conduit for controlling the amount'of oil admitted to the mixing pump.

8. In a pumping apparatus for burners, a pump casing, the pump casing having a fuel supply-pump compartment and an air-pump compartment and a fuel return-pump compartment and a drainage compartment formed the =in a pair of shafts rotatably mounted in the casing and extonding to allv of the th *ce pump eompmftments, one of the shafts being entirely bnclose'l Within the pump casing ai'id the er sea ft extending at the drive-end th:` the di'ainage compartment and the pump leasing, the di'ainage eompa trio-nt being adapted to'intei'cept fuel leakage through the casing along; said other shat, a sump Casing' located beneath the pump casing andhaving an air inlet opening for-med therein, a eonduit for conveying liquid fnel from the supply-pump eompartinent to the air-pump compartment, other conduits eonnecting each compartment with the sump casing so as to supply liquid fuel to the'return-pump compartment and air to the air-pump compai'tment and to convey liquid fuel from the drainage compartment to 'the snmp When the shafts are rotating, said condnits also serving to conve; dr'ainage from all the compartments When the shafts eease to i'otate, and means for rotating both' shafts.

9. In a pumping apparatus for oil burners, a source of oil supply, a hurner nozzle, a sump 'having an air inlet opening formed therein, a casing mounted above the sump so as to drain into the sump, the casing having foi'med therein an air-pump compartment with an inlet communicating withthe upper part of the sump and a discharge Outlet, the casing having formed thei'ein also an oil return-pump compartment with an ontlet communicating With the source of supply and an inlet communicating With a predetermined level in the sump so as to convey any oil tending to rise abovesaid level to the i'etnrn-pmnp compartment, the casing having formed therein also an oil supply-pump compartment With an inlet communicating with the source of supply and an Outlet cornmnnicating With the sump and a passage connecting the Outlet of the supply-pump compartment with the inlet of the air-pump compartment, impelling means Inovably mounted in the compartments, and restricting means in said Outlet from the supply-pump compartment communicating with the sump for creating a back pressure in the' passage to induce a flow of o il to the air-pump compartment.

10. In a pumping unit for burners, a snmp having an air inlet opening formed therein, a casing mounted above the sump so as to drain into the sump, the casing having formed therein an air-pump compartment with an inlet communicating With the upper part of the sump, the casing having'formed therein also a fuel return-pump compartment With an inlet communicating with a predetermined level in the sump so as to convey anj7 fuel tending to l'ise above said level to the return-pump compartment, the casing having'formed therein also a vfuel supplypump compartment with a passage connecting the outlet of the supply-pump compart`I ment Withthe inl'et of the air-pump compartment, throttling means in said passage,

impelling means movahly mounted' in the fuel.

FRANK FISCHER.. GUDMUND SEVERTSEN. 

